1. Field of the Invention
The invention relates to a device for indicating when a set value of a clamping force of a tightenable clamp has been reached, wherein the tightenable clamp is comprised of a substantially C-shaped clamp strip having radially inwardly pointing end face walls at its axial ends and having clamping jaws provided on the end portions extending in the circumferential direction.
2. Description of the Related Art
In known clamps of this kind (DE 198 02 676 C1), which are used, for example, as pipe couplings for axially connecting two pipes, the clamping jaws are connected by at least one clamping screw which is tightened by a torque wrench in order to apply a predetermined force. The torque adjusted on the torque wrench, however, is not in all situations a precise measure for the set value of the clamping force. For example, when the screws are greased or provided with a washer or have different types of coatings, different radial clamping forces result for the clamp, and this leads to different mounting and operating results.